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- /*
- net_packet.c -- Handles in- and outgoing VPN packets
- Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2014 Guus Sliepen <guus@tinc-vpn.org>
- 2010 Timothy Redaelli <timothy@redaelli.eu>
- 2010 Brandon Black <blblack@gmail.com>
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License along
- with this program; if not, write to the Free Software Foundation, Inc.,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
- #include "system.h"
- #include <openssl/rand.h>
- #include <openssl/err.h>
- #include <openssl/evp.h>
- #include <openssl/pem.h>
- #include <openssl/hmac.h>
- #ifdef HAVE_ZLIB
- #include <zlib.h>
- #endif
- #ifdef HAVE_LZO
- #include LZO1X_H
- #endif
- #include "avl_tree.h"
- #include "conf.h"
- #include "connection.h"
- #include "device.h"
- #include "ethernet.h"
- #include "event.h"
- #include "graph.h"
- #include "logger.h"
- #include "net.h"
- #include "netutl.h"
- #include "protocol.h"
- #include "process.h"
- #include "route.h"
- #include "utils.h"
- #include "xalloc.h"
- int keylifetime = 0;
- int keyexpires = 0;
- #ifdef HAVE_LZO
- static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
- #endif
- static void send_udppacket(node_t *, vpn_packet_t *);
- unsigned replaywin = 16;
- bool localdiscovery = false;
- #define MAX_SEQNO 1073741824
- /* mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
- mtuprobes == 31: sleep pinginterval seconds
- mtuprobes == 32: send 1 burst, sleep pingtimeout second
- mtuprobes == 33: no response from other side, restart PMTU discovery process
- Probes are sent in batches of at least three, with random sizes between the
- lower and upper boundaries for the MTU thus far discovered.
- After the initial discovery, a fourth packet is added to each batch with a
- size larger than the currently known PMTU, to test if the PMTU has increased.
- In case local discovery is enabled, another packet is added to each batch,
- which will be broadcast to the local network.
- */
- void send_mtu_probe(node_t *n) {
- vpn_packet_t packet;
- int len, i;
- int timeout = 1;
-
- n->mtuprobes++;
- n->mtuevent = NULL;
- if(!n->status.reachable || !n->status.validkey) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
- n->mtuprobes = 0;
- return;
- }
- if(n->mtuprobes > 32) {
- if(!n->minmtu) {
- n->mtuprobes = 31;
- timeout = pinginterval;
- goto end;
- }
- ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
- n->mtuprobes = 1;
- n->minmtu = 0;
- n->maxmtu = MTU;
- }
- if(n->mtuprobes >= 10 && n->mtuprobes < 32 && !n->minmtu) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
- n->mtuprobes = 31;
- }
- if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
- if(n->minmtu > n->maxmtu)
- n->minmtu = n->maxmtu;
- else
- n->maxmtu = n->minmtu;
- n->mtu = n->minmtu;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
- n->mtuprobes = 31;
- }
- if(n->mtuprobes == 31) {
- timeout = pinginterval;
- goto end;
- } else if(n->mtuprobes == 32) {
- timeout = pingtimeout;
- }
- for(i = 0; i < 4 + localdiscovery; i++) {
- if(i == 0) {
- if(n->mtuprobes < 30 || n->maxmtu + 8 >= MTU)
- continue;
- len = n->maxmtu + 8;
- } else if(n->maxmtu <= n->minmtu) {
- len = n->maxmtu;
- } else {
- len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
- }
- if(len < 64)
- len = 64;
-
- memset(packet.data, 0, 14);
- RAND_pseudo_bytes(packet.data + 14, len - 14);
- packet.len = len;
- if(i >= 4 && n->mtuprobes <= 10)
- packet.priority = -1;
- else
- packet.priority = 0;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
- send_udppacket(n, &packet);
- }
- end:
- n->mtuevent = new_event();
- n->mtuevent->handler = (event_handler_t)send_mtu_probe;
- n->mtuevent->data = n;
- n->mtuevent->time = now + timeout;
- event_add(n->mtuevent);
- }
- void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
- if(!packet->data[0]) {
- packet->data[0] = 1;
- send_udppacket(n, packet);
- } else {
- if(n->mtuprobes > 30) {
- if (len == n->maxmtu + 8) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname);
- n->maxmtu = MTU;
- n->mtuprobes = 10;
- return;
- }
- if(n->minmtu)
- n->mtuprobes = 30;
- else
- n->mtuprobes = 1;
- }
- if(len > n->maxmtu)
- len = n->maxmtu;
- if(n->minmtu < len)
- n->minmtu = len;
- }
- }
- static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
- if(level == 0) {
- memcpy(dest, source, len);
- return len;
- } else if(level == 10) {
- #ifdef HAVE_LZO
- lzo_uint lzolen = MAXSIZE;
- lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem);
- return lzolen;
- #else
- return -1;
- #endif
- } else if(level < 10) {
- #ifdef HAVE_ZLIB
- unsigned long destlen = MAXSIZE;
- if(compress2(dest, &destlen, source, len, level) == Z_OK)
- return destlen;
- else
- #endif
- return -1;
- } else {
- #ifdef HAVE_LZO
- lzo_uint lzolen = MAXSIZE;
- lzo1x_999_compress(source, len, dest, &lzolen, lzo_wrkmem);
- return lzolen;
- #else
- return -1;
- #endif
- }
-
- return -1;
- }
- static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
- if(level == 0) {
- memcpy(dest, source, len);
- return len;
- } else if(level > 9) {
- #ifdef HAVE_LZO
- lzo_uint lzolen = MAXSIZE;
- if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK)
- return lzolen;
- else
- #endif
- return -1;
- }
- #ifdef HAVE_ZLIB
- else {
- unsigned long destlen = MAXSIZE;
- if(uncompress(dest, &destlen, source, len) == Z_OK)
- return destlen;
- else
- return -1;
- }
- #endif
- return -1;
- }
- /* VPN packet I/O */
- static void receive_packet(node_t *n, vpn_packet_t *packet) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
- packet->len, n->name, n->hostname);
- route(n, packet);
- }
- static bool try_mac(const node_t *n, const vpn_packet_t *inpkt) {
- unsigned char hmac[EVP_MAX_MD_SIZE];
- if(!n->indigest || !n->inmaclength || !n->inkey || inpkt->len < sizeof inpkt->seqno + n->inmaclength)
- return false;
- HMAC(n->indigest, n->inkey, n->inkeylength, (unsigned char *) &inpkt->seqno, inpkt->len - n->inmaclength, (unsigned char *)hmac, NULL);
- return !memcmp_constant_time(hmac, (char *) &inpkt->seqno + inpkt->len - n->inmaclength, n->inmaclength);
- }
- static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
- vpn_packet_t pkt1, pkt2;
- vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
- int nextpkt = 0;
- vpn_packet_t *outpkt = pkt[0];
- int outlen, outpad;
- unsigned char hmac[EVP_MAX_MD_SIZE];
- int i;
- if(!n->inkey) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
- n->name, n->hostname);
- return;
- }
- /* Check packet length */
- if(inpkt->len < sizeof(inpkt->seqno) + n->inmaclength) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)",
- n->name, n->hostname);
- return;
- }
- /* Check the message authentication code */
- if(n->indigest && n->inmaclength) {
- inpkt->len -= n->inmaclength;
- HMAC(n->indigest, n->inkey, n->inkeylength,
- (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
- if(memcmp_constant_time(hmac, (char *) &inpkt->seqno + inpkt->len, n->inmaclength)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)",
- n->name, n->hostname);
- return;
- }
- }
- /* Decrypt the packet */
- if(n->incipher) {
- outpkt = pkt[nextpkt++];
- if(!EVP_DecryptInit_ex(&n->inctx, NULL, NULL, NULL, NULL)
- || !EVP_DecryptUpdate(&n->inctx, (unsigned char *) &outpkt->seqno, &outlen,
- (unsigned char *) &inpkt->seqno, inpkt->len)
- || !EVP_DecryptFinal_ex(&n->inctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s): %s",
- n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
- return;
- }
-
- outpkt->len = outlen + outpad;
- inpkt = outpkt;
- }
- /* Check the sequence number */
- inpkt->len -= sizeof(inpkt->seqno);
- inpkt->seqno = ntohl(inpkt->seqno);
- if(replaywin) {
- if(inpkt->seqno != n->received_seqno + 1) {
- if(inpkt->seqno >= n->received_seqno + replaywin * 8) {
- if(n->farfuture++ < replaywin >> 2) {
- logger(LOG_WARNING, "Packet from %s (%s) is %d seqs in the future, dropped (%u)",
- n->name, n->hostname, inpkt->seqno - n->received_seqno - 1, n->farfuture);
- return;
- }
- logger(LOG_WARNING, "Lost %d packets from %s (%s)",
- inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
- memset(n->late, 0, replaywin);
- } else if (inpkt->seqno <= n->received_seqno) {
- if((n->received_seqno >= replaywin * 8 && inpkt->seqno <= n->received_seqno - replaywin * 8) || !(n->late[(inpkt->seqno / 8) % replaywin] & (1 << inpkt->seqno % 8))) {
- logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
- n->name, n->hostname, inpkt->seqno, n->received_seqno);
- return;
- }
- } else {
- for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
- n->late[(i / 8) % replaywin] |= 1 << i % 8;
- }
- }
- n->farfuture = 0;
- n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
- }
- if(inpkt->seqno > n->received_seqno)
- n->received_seqno = inpkt->seqno;
-
- if(n->received_seqno > MAX_SEQNO)
- keyexpires = 0;
- /* Decompress the packet */
- length_t origlen = inpkt->len;
- if(n->incompression) {
- outpkt = pkt[nextpkt++];
- if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) {
- ifdebug(TRAFFIC) logger(LOG_ERR, "Error while uncompressing packet from %s (%s)",
- n->name, n->hostname);
- return;
- }
- inpkt = outpkt;
- origlen -= MTU/64 + 20;
- }
- inpkt->priority = 0;
- if(!inpkt->data[12] && !inpkt->data[13])
- mtu_probe_h(n, inpkt, origlen);
- else
- receive_packet(n, inpkt);
- }
- void receive_tcppacket(connection_t *c, const char *buffer, int len) {
- vpn_packet_t outpkt;
- if(len > sizeof outpkt.data)
- return;
- outpkt.len = len;
- if(c->options & OPTION_TCPONLY)
- outpkt.priority = 0;
- else
- outpkt.priority = -1;
- memcpy(outpkt.data, buffer, len);
- receive_packet(c->node, &outpkt);
- }
- static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
- vpn_packet_t pkt1, pkt2;
- vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
- vpn_packet_t *inpkt = origpkt;
- int nextpkt = 0;
- vpn_packet_t *outpkt;
- int origlen;
- int outlen, outpad;
- #if defined(SOL_IP) && defined(IP_TOS)
- static int priority = 0;
- #endif
- int origpriority;
- if(!n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
- return;
- }
- /* Make sure we have a valid key */
- if(!n->status.validkey) {
- ifdebug(TRAFFIC) logger(LOG_INFO,
- "No valid key known yet for %s (%s), forwarding via TCP",
- n->name, n->hostname);
- if(n->last_req_key + 10 <= now) {
- send_req_key(n);
- n->last_req_key = now;
- }
- send_tcppacket(n->nexthop->connection, origpkt);
- return;
- }
- if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
- ifdebug(TRAFFIC) logger(LOG_INFO,
- "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
- n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
- if(n != n->nexthop)
- send_packet(n->nexthop, origpkt);
- else
- send_tcppacket(n->nexthop->connection, origpkt);
- return;
- }
- origlen = inpkt->len;
- origpriority = inpkt->priority;
- /* Compress the packet */
- if(n->outcompression) {
- outpkt = pkt[nextpkt++];
- if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) {
- ifdebug(TRAFFIC) logger(LOG_ERR, "Error while compressing packet to %s (%s)",
- n->name, n->hostname);
- return;
- }
- inpkt = outpkt;
- }
- /* Add sequence number */
- inpkt->seqno = htonl(++(n->sent_seqno));
- inpkt->len += sizeof(inpkt->seqno);
- /* Encrypt the packet */
- if(n->outcipher) {
- outpkt = pkt[nextpkt++];
- if(!EVP_EncryptInit_ex(&n->outctx, NULL, NULL, NULL, NULL)
- || !EVP_EncryptUpdate(&n->outctx, (unsigned char *) &outpkt->seqno, &outlen,
- (unsigned char *) &inpkt->seqno, inpkt->len)
- || !EVP_EncryptFinal_ex(&n->outctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
- ifdebug(TRAFFIC) logger(LOG_ERR, "Error while encrypting packet to %s (%s): %s",
- n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
- goto end;
- }
- outpkt->len = outlen + outpad;
- inpkt = outpkt;
- }
- /* Add the message authentication code */
- if(n->outdigest && n->outmaclength) {
- HMAC(n->outdigest, n->outkey, n->outkeylength, (unsigned char *) &inpkt->seqno,
- inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
- inpkt->len += n->outmaclength;
- }
- /* Determine which socket we have to use */
- if(n->address.sa.sa_family != listen_socket[n->sock].sa.sa.sa_family) {
- for(int sock = 0; sock < listen_sockets; sock++) {
- if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family) {
- n->sock = sock;
- break;
- }
- }
- }
- /* Send the packet */
- struct sockaddr *sa;
- socklen_t sl;
- int sock;
- sockaddr_t broadcast;
- /* Overloaded use of priority field: -1 means local broadcast */
- if(origpriority == -1 && n->prevedge) {
- sock = rand() % listen_sockets;
- memset(&broadcast, 0, sizeof broadcast);
- if(listen_socket[sock].sa.sa.sa_family == AF_INET6) {
- broadcast.in6.sin6_family = AF_INET6;
- broadcast.in6.sin6_addr.s6_addr[0x0] = 0xff;
- broadcast.in6.sin6_addr.s6_addr[0x1] = 0x02;
- broadcast.in6.sin6_addr.s6_addr[0xf] = 0x01;
- broadcast.in6.sin6_port = n->prevedge->address.in.sin_port;
- broadcast.in6.sin6_scope_id = listen_socket[sock].sa.in6.sin6_scope_id;
- } else {
- broadcast.in.sin_family = AF_INET;
- broadcast.in.sin_addr.s_addr = -1;
- broadcast.in.sin_port = n->prevedge->address.in.sin_port;
- }
- sa = &broadcast.sa;
- sl = SALEN(broadcast.sa);
- } else {
- if(origpriority == -1)
- origpriority = 0;
- sa = &(n->address.sa);
- sl = SALEN(n->address.sa);
- sock = n->sock;
- }
- #if defined(SOL_IP) && defined(IP_TOS)
- if(priorityinheritance && origpriority != priority
- && listen_socket[n->sock].sa.sa.sa_family == AF_INET) {
- priority = origpriority;
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
- if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
- logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
- }
- #endif
- if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) {
- if(sockmsgsize(sockerrno)) {
- if(n->maxmtu >= origlen)
- n->maxmtu = origlen - 1;
- if(n->mtu >= origlen)
- n->mtu = origlen - 1;
- } else
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
- }
- end:
- origpkt->len = origlen;
- }
- /*
- send a packet to the given vpn ip.
- */
- void send_packet(const node_t *n, vpn_packet_t *packet) {
- node_t *via;
- if(n == myself) {
- if(overwrite_mac)
- memcpy(packet->data, mymac.x, ETH_ALEN);
- devops.write(packet);
- return;
- }
- ifdebug(TRAFFIC) logger(LOG_ERR, "Sending packet of %d bytes to %s (%s)",
- packet->len, n->name, n->hostname);
- if(!n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Node %s (%s) is not reachable",
- n->name, n->hostname);
- return;
- }
- via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via;
- if(via != n)
- ifdebug(TRAFFIC) logger(LOG_INFO, "Sending packet to %s via %s (%s)",
- n->name, via->name, n->via->hostname);
- if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) {
- if(!send_tcppacket(via->connection, packet))
- terminate_connection(via->connection, true);
- } else
- send_udppacket(via, packet);
- }
- /* Broadcast a packet using the minimum spanning tree */
- void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
- avl_node_t *node;
- connection_t *c;
- node_t *n;
- // Always give ourself a copy of the packet.
- if(from != myself)
- send_packet(myself, packet);
- // In TunnelServer mode, do not forward broadcast packets.
- // The MST might not be valid and create loops.
- if(tunnelserver || broadcast_mode == BMODE_NONE)
- return;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
- packet->len, from->name, from->hostname);
- switch(broadcast_mode) {
- // In MST mode, broadcast packets travel via the Minimum Spanning Tree.
- // This guarantees all nodes receive the broadcast packet, and
- // usually distributes the sending of broadcast packets over all nodes.
- case BMODE_MST:
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
- if(c->status.active && c->status.mst && c != from->nexthop->connection)
- send_packet(c->node, packet);
- }
- break;
- // In direct mode, we send copies to each node we know of.
- // However, this only reaches nodes that can be reached in a single hop.
- // We don't have enough information to forward broadcast packets in this case.
- case BMODE_DIRECT:
- if(from != myself)
- break;
- for(node = node_udp_tree->head; node; node = node->next) {
- n = node->data;
- if(n->status.reachable && n != myself && ((n->via == myself && n->nexthop == n) || n->via == n))
- send_packet(n, packet);
- }
- break;
- default:
- break;
- }
- }
- static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
- avl_node_t *node;
- edge_t *e;
- node_t *n = NULL;
- static time_t last_hard_try = 0;
- for(node = edge_weight_tree->head; node; node = node->next) {
- e = node->data;
- if(e->to == myself)
- continue;
- if(last_hard_try == now && sockaddrcmp_noport(from, &e->address))
- continue;
- if(!try_mac(e->to, pkt))
- continue;
- n = e->to;
- break;
- }
- last_hard_try = now;
- return n;
- }
- void handle_incoming_vpn_data(int sock) {
- vpn_packet_t pkt;
- char *hostname;
- sockaddr_t from;
- socklen_t fromlen = sizeof(from);
- node_t *n;
- pkt.len = recvfrom(listen_socket[sock].udp, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
- if(pkt.len < 0) {
- if(!sockwouldblock(sockerrno))
- logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
- return;
- }
- sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
- n = lookup_node_udp(&from);
- if(!n) {
- n = try_harder(&from, &pkt);
- if(n)
- update_node_udp(n, &from);
- else ifdebug(PROTOCOL) {
- hostname = sockaddr2hostname(&from);
- logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
- free(hostname);
- return;
- }
- else
- return;
- }
- n->sock = sock;
- receive_udppacket(n, &pkt);
- }
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